/**
 * 生产环境配置
 */

const helpers = require('./helpers');
const webpackMerge = require('webpack-merge'); // used to merge webpack configs
const commonConfig = require('./webpack.common.js'); // the settings that are common to prod and dev

/**
 * Webpack Plugins
 */
const DefinePlugin = require('webpack/lib/DefinePlugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const IgnorePlugin = require('webpack/lib/IgnorePlugin');
const LoaderOptionsPlugin = require('webpack/lib/LoaderOptionsPlugin');
const NormalModuleReplacementPlugin = require('webpack/lib/NormalModuleReplacementPlugin');
const ProvidePlugin = require('webpack/lib/ProvidePlugin');
const UglifyJsPlugin = require('webpack/lib/optimize/UglifyJsPlugin');
const OptimizeJsPlugin = require('optimize-js-plugin');

/**
 * Webpack Constants
 */
const ENV = process.env.NODE_ENV = process.env.ENV = 'production';
const HOST = process.env.HOST || 'localhost';
const PORT = process.env.PORT || 8080;
const METADATA = webpackMerge(commonConfig({
  env: ENV
}).metadata, {
  host: HOST,
  port: PORT,
  ENV: ENV,
  HMR: false
});

module.exports = function (env) {
  
  /**
   * 把common和prod的配置项合并
   */
  return webpackMerge(commonConfig({
    env: ENV
  }), {
    
    /**
     * Webpack 打包方式支持生产环境的原始代码
     */
    devtool: 'source-map',

    output: {
      path: helpers.root('dist'),
      filename: '[name].[chunkhash].bundle.js',
      sourceMapFilename: '[name].[chunkhash].bundle.map',
      chunkFilename: '[id].[chunkhash].chunk.js'
    },

    module: {

      rules: [

        {
          test: /\.css$/,
          loader: ExtractTextPlugin.extract({
            fallback: 'style-loader',
            use: 'css-loader'
          }),
          include: [helpers.root('src', 'styles')]
        },

        {
          test: /\.scss$/,
          loader: ExtractTextPlugin.extract({
            fallback: 'style-loader',
            use: 'css-loader!sass-loader'
          }),
          include: [helpers.root('src', 'styles')]
        },

      ]

    },

    plugins: [
  
  
      /**
       * 让js文件更快被加载
       */
      new OptimizeJsPlugin({
        sourceMap: false
      }),

      /**
       * 从Webpack中提取CSS文件并存为单独的文件。
       * @example:  require('style.css');
       */
      new ExtractTextPlugin('[name].[contenthash].css'),
  
      /**
       * 在构建时申明常量（内置方法）区分当前环境
       */
      // NOTE: when adding more properties make sure you include them in custom-typings.d.ts
      new DefinePlugin({
        'ENV': JSON.stringify(METADATA.ENV),
        'HMR': METADATA.HMR,
        'process.env': {
          'ENV': JSON.stringify(METADATA.ENV),
          'NODE_ENV': JSON.stringify(METADATA.ENV),
          'HMR': METADATA.HMR,
        }
      }),

      /**
       * 压缩JS文件
       */
      // NOTE: To debug prod builds uncomment //debug lines and comment //prod lines
      new UglifyJsPlugin({
        
        /*
         * Debug 模式
        beautify: true,
        mangle: false,
        dead_code: false,
        unused: false,
        deadCode: false,
        compress: {
          screw_ie8: true,
          keep_fnames: true,
          drop_debugger: false,
          dead_code: false,
          unused: false
        },
        comments: true,
        */


        beautify: false, //prod
        output: {
          comments: false
        },
        //prod
        mangle: {
          screw_ie8: true
        },
        //prod
        compress: {
          screw_ie8: true,
          warnings: false,
          conditionals: true,
          unused: true,
          comparisons: true,
          sequences: true,
          dead_code: true,
          evaluate: true,
          if_return: true,
          join_vars: true,
          negate_iife: false // we need this for lazy v8
        },
      }),

      /**
       * 用empty.js替换Angular2的热替换和zone.js
       */
      new NormalModuleReplacementPlugin(
        /angular2-hmr/,
        helpers.root('config/empty.js')
      ),

      new NormalModuleReplacementPlugin(
        /zone\.js(\\|\/)dist(\\|\/)long-stack-trace-zone/,
        helpers.root('config/empty.js')
      ),


      // AoT
      new NormalModuleReplacementPlugin(
        /@angular(\\|\/)upgrade/,
        helpers.root('config/empty.js')
      ),
      new NormalModuleReplacementPlugin(
        /@angular(\\|\/)compiler/,
        helpers.root('config/empty.js')
      ),
      new NormalModuleReplacementPlugin(
        /@angular(\\|\/)platform-browser-dynamic/,
        helpers.root('config/empty.js')
      ),
      new NormalModuleReplacementPlugin(
        /dom(\\|\/)debug(\\|\/)ng_probe/,
        helpers.root('config/empty.js')
      ),
      new NormalModuleReplacementPlugin(
        /dom(\\|\/)debug(\\|\/)by/,
        helpers.root('config/empty.js')
      ),
      new NormalModuleReplacementPlugin(
        /src(\\|\/)debug(\\|\/)debug_node/,
        helpers.root('config/empty.js')
      ),
      new NormalModuleReplacementPlugin(
        /src(\\|\/)debug(\\|\/)debug_renderer/,
        helpers.root('config/empty.js')
      ),

      /**
       * Plugin: CompressionPlugin
       * Description: Prepares compressed versions of assets to serve
       * them with Content-Encoding
       *
       * See: https://github.com/webpack/compression-webpack-plugin
       */
      //  install compression-webpack-plugin
      // new CompressionPlugin({
      //   regExp: /\.css$|\.html$|\.js$|\.map$/,
      //   threshold: 2 * 1024
      // })

      /**
       * Plugin LoaderOptionsPlugin (experimental)
       *
       * See: https://gist.github.com/sokra/27b24881210b56bbaff7
       */
      new LoaderOptionsPlugin({
        minimize: true,
        debug: false,
        options: {

          /**
           * Html loader advanced options
           *
           * See: https://github.com/webpack/html-loader#advanced-options
           */
          // TODO: Need to workaround Angular 2's html syntax => #id [bind] (event) *ngFor
          htmlLoader: {
            minimize: true,
            removeAttributeQuotes: false,
            caseSensitive: true,
            customAttrSurround: [
              [/#/, /(?:)/],
              [/\*/, /(?:)/],
              [/\[?\(?/, /(?:)/]
            ],
            customAttrAssign: [/\)?\]?=/]
          },

        }
      }),

      /**
       * Plugin: BundleAnalyzerPlugin
       * Description: Webpack plugin and CLI utility that represents
       * bundle content as convenient interactive zoomable treemap
       *
       * `npm run build:prod -- --env.analyze` to use
       *
       * See: https://github.com/th0r/webpack-bundle-analyzer
       */

    ],

    node: {
      global: true,
      crypto: 'empty',
      process: false,
      module: false,
      clearImmediate: false,
      setImmediate: false
    }

  });
}
